The present invention relates to blowing apparatus of the type having a centrifugal fan driven by a gasoline engine or electric motor and more particularly to a light and compact body suspensible from one's shoulder both for use and conveyance.
High-pressure blowers are known that are provided with a centrifugal fan and carried on one's back. Such blowers are usually equipped with an exchangeable one-sided, generally right-handed blowing nozzle and therefore are awkward to do tasks on the left. It is often the case that a blowing operation accompanies another work, such as water-sprinkling, repairing gutters and downspouts, and carrying garbage cans, it is troublesome to load and unload the blower onto and from the operator's back whenever the type of work changes.
In accordance with the invention, the apparatus has interiorly a prime mover and a centrifugal fan and exteriorly a housing and a blowing nozzle centrally joined to the housing. The fan has a rotor provided with a plurality of curved vanes and a casing common to the housing. The housing consists of front, mid and rear coverings, the rear covering being peripherally joined to the mid covering. The mid covering is composed of an outer cylindrical wall, an inner conical wall peripherally fixed to the cylindrical wall, a plurality of cross-sectionally streamline stays inwardly radially extending from the cylindrical wall behind the conical wall, and a central ring supported by the stays. The prime mover has its casing removably secured to the central ring and the output shaft directly coupled with the rotor. The front covering is interiorly formed with fixed vanes similar in number and shape to the rotary vanes on the rotor and air-tightly connected to the mid covering to define an annular space together with the cylindrical and conical walls. The space has as an axial entrance an annular gap defined by the inner periphery of the conical wall and as an axial exit the central bore in the front covering. The rotor is disposed in the space to have a predetermined clearance between the fixed vanes and the conical and cylindrical walls. The blowing nozzle and the front and rear coverings are made of synthetic plastics and the mid covering and the rotor are made of light metal or synthetic plastics.
A handle and a shoulder belt are attached to the housing. Spongy pads are affixed on the both sides of the housing so as to prevent uncomfortable vibrations from being transmitted to one who operates it. A pair of feet are mounted on the underside of the housing and occasionally wheeled for convenience. The apparatus is simple in construction, compact and light enough to be suspended from one's shoulder by a shoulder belt or carried in a hand by a handle in a substantially horizontal position. Upon rotation of the rotor, air is sucked from the back side of the apparatus to flow around the prime mover. The air is straightened by the streamline stays prior to entering the space through the axial entrance. The air in the rear side of the space is centrifugally compressed along the rotary vanes to peripherally shift to the front side of the space. Then, the compressed air is centripetally guided along the fixed vanes to flow toward the blowing nozzle through the axial exit.
In summary, it is the primary object of the present invention to provide a suspensible blowing apparatus of the type having a relatively high-pressure centrifugal fan.
Other objects, features and advantages of the invention will appear more fully from the detailed description given hereinafter.